Option Compare Database
Option Explicit

Public Function fnUpdateOrderRef() As Boolean
 Dim sCustRef As String
 Dim sDelPostcode As String
 Dim sOrderRef As String
 Dim rs As DAO.Recordset
 Set rs = CurrentDb.OpenRecordset("select autoId from tbl_empdets where smesos_id=""" & user & """;")
 rs.MoveFirst
 sCustRef = rs!CustRef
 sDelPostcode = rs!DelPostcode
 sOrderRef = rs!OrderRef
Next_Record:
 rs.MoveNext
 If rs.EOF Then Exit Function
 If rs!CustRef = sCustRef And rs!DelPostcode = sDelPostcode Then
  rs.Edit
  rs!OrderRef = sOrderRef
  rs.Update
 Else
  sCustRef = rs!CustRef
  sDelPostcode = rs!DelPostcode
  sOrderRef = rs!OrderRef
 End If
 GoTo Next_Record
End Function

Sub test()
 Call fnUpdateOrderRef
End Sub